CarbSync

Video for 2007 model

For those people who prefer video, and have a newer bike, there is a video of the process, from start to finish, at http://www.youtube.com/watch?v=NYt33GRHzww There's also a video for "older bikes", at http://www.youtube.com/watch?v=dYImsgp7g-Q

Carburettor balancing/synchronising on a GS500 K2 2002+

Since none of the GS500 manuals in circulation have a correct picture of where the vacuum ports are located on the carburettors of a 2002+ bike and having spent 20 minutes looking at the carburettors without a clue as to where to connect the vacuum gauge tubes I thought that I would document my eventual success in synchronising them.

Tools needed:

Carb Balancer Synchroniser Vacuum Gauge with at least 2 dials. (or the el cheapo version )
The manuals recommend that you make a spare fuel tank but if you are not inclined to do so you could either get a friend/family member to help by holding the bike's fuel tank
a Philips screw driver and a flat one
a chair

Steps involved:

Remove the 2 bolts holding the fuel tank
Turn the tap under the fuel tank to the off position with a flat screwdriver
Disconnect the 3 rubber hoses from under the fuel tank and make sure that you know how they go back(make a mark on them somehow)
(skip this step if you have a spare fuel tank)bring the chair to the left of the bike and rest the fuel tank(place some books underneath it as it needs to be high enough to feed the carbs) on it in an upright position. Now pass the fuel lines through the frame of the bike and connect them back to the fuel tank. turn the tap underneath the tank to the on position. (editor: ALTERNATIVELY... buy a little plastic funnel, shove it into the main fuel line going into the carb, and tape it upright, to the frame then poor some gasoline in there ! See @2:15, http://www.youtube.com/watch?v=dYImsgp7g-Q )
Turn the other fuel tap to Prime
disconnect the tube from the first vacuum port(right carburettor) and connect the tube of the vacuum gauge to it(to the port not the removed tube dummy)
now this is where I got stuck and eventually my brother managed to find the second port under the choke spring covered by a black rubber cap. fiddle with the cap until you can get it off and make sure you do not drop it. Now feed the second tube of the vacuum gauge to it and start the engine
Let the engine warm up until it idles at ~1100 rpm and then increase the idle to ~1750 rpm. Now find the synchronisation screw and twist it until you get the right readings on the vacuum gauges. see 6th post
reverse everything making sure you turn the fuel tap back to on :oops otherwise when you are all done and testing your bike you do not panic once it stalls and will not start again.

Thank your lucky stars you do not have to do it again for another 4000 miles.In conclusion I found this to be a 2 man job if you do not have a temporary fuel tank to use.

Vacuum ports location